Statistics review

Census

________: collect data from every individual in the population.

Sample

________: subset of individuals in a population from which we actually collect data.

Undercoverage

________: occurs when some members of the population are less likely to be chosen or can not be chosen in a sample.

Experimental Unit

________: object to which a treatment is randomly assigned.

Replication

________: using enough experimental units to distinguish a difference in the effects of the treatments from chance variation due to the random assignment.

Retrospective

________: Examines existing data for a sample of individuals.

Individual

________: object described in a set of data → people, animals, things.

Convenience

________: choosing individuals from the population who are easy to reach results in a(n) ________ sample.

Cluster

________ sampling → selects a sample by randomly choosing ________ and including each member of the selected ________ in the sample.

Prospective

________: Tracks individuals into the future.

Levels

________: different values of a factor.

systematic

___________: selects a sample from an ordered arrangement of the population by randomly selecting one of the first k individuals and choosing every Kth individual thereafter.

Control Group

________: used to provide a baseline for comparing the effects of other treatments.

Single blind

________: either the subject or those who interact and measure the response don't know which subjects are getting which treatment.

Non response

________: occurs when an individual chosen for the sample cant be contacted or refuses to participate.

Population

________: entire group of individuals we want information about.

Response Bias

________: occurs when there is a systematic pattern of inaccurate answers to a survey question.

Factor

________: variable thats manipulated and may cause a change in the response variable.

Placebo

________: treatment that has no active ingredient, but is otherwise like other treatments.

Voluntary Response Sampling

________: allows people to choose to be in the sample by responding to a general invitation.

Estimates

________ from larger samples are more precise opposed to smaller samples.

Block

________: group of experimental units known BEFORE EXPERIMENT to be similar in some way that is expected to affect the response to the treatment.

Double blind

________: neither the subject or those who interact with and measure responses know which treatment the subject received.

Randomized Block Design

________: in each block, experimental units are randomly assigned to treatments.

Placebo Effect

________: describes the fact that some subjects in an experiment will respond favorably to any treatment.

subject

_________: when the experimental unit is human.

Population

entire group of individuals we want information about

Census

collect data from every individual in the population

Sample

subset of individuals in a population from which we actually collect data

Individual

object described in a set of data → people, animals, things

Convenience

choosing individuals from the population who are easy to reach results in a convenience sample

Voluntary Response Sampling

allows people to choose to be in the sample by responding to a general invitation

Simple random sample

involves using a chance process to determine which members of a population are included in the sample

Stratified random sampling

selects a sample by choosing a simple random sample from each stratum and combining the simple random samples into one overall sample

Systematic

selects a sample from an ordered arrangement of the population by randomly selecting one of the first K individuals and choosing every Kth individual thereafter

Non-response

occurs when an individual chosen for the sample cant be contacted or refuses to participate

Response Bias

occurs when there is a systematic pattern of inaccurate answers to a survey question

Undercoverage

occurs when some members of the population are less likely to be chosen or cannot be chosen in a sample

Retrospective

Examines existing data for a sample of individuals

Prospective

Tracks individuals into the future

Control Group

used to provide a baseline for comparing the effects of other treatments

Experimental Unit

object to which a treatment is randomly assigned

Subject

when the experimental unit is human

Treatment

specific condition applied to individuals in an experiment

Factor

variable thats manipulated and may cause a change in the response variable

Levels

different values of a factor

Placebo

treatment that has no active ingredient, but is otherwise like other treatments

Placebo Effect

describes the fact that some subjects in an experiment will respond favorably to any treatment

Confounding Variables

two variables are associated when their effects on a response variable are the same

Double blind

neither the subject or those who interact with and measure responses know which treatment the subject received

Single blind

either the subject or those who interact and measure the response don't know which subjects are getting which treatment

Replication

using enough experimental units to distinguish a difference in the effects of the treatments from chance variation due to the random assignment

Random Assignment

experimental units are assigned to treatments using a chance process

Randomized Block Design

in each block, experimental units are randomly assigned to treatments

Block

group of experimental units known BEFORE EXPERIMENT to be similar in some way that is expected to affect the response to the treatment

Matched Pairs

pairing, easy to compare

Sampling Variability

refers to the fact that different random samples of the same size from the same population produce different estimates

Study

there are criteria for establishing causation when you cant perform an experiment; dont just assume one thing causes another

Confidential

All individual data must be kept __________; only statistical group summaries can be made public

Consent

Subjects must give _______